CAUSE AND EFFECT

GABA

Provides the sole inhibitory output from the cerebellar cortex and projects to deep cerebellar nuclei and the vestibular nucleus

Ataxia

Clinical disorder of the cerebellum characterized by lack of coordination, delay in initiation of movement, and poor execution of movement sequences

Dysdiadochokinesia

The inability to perform rapid alternating movements, a symptom of cerebellar disorders

Rebound phenomenon

The inability to stop a movement, a symptom of cerebellar disorders

Cerebellum

Functions for motor coordination (rate, range, direction of movement), evaluates disparities between intended and actual action, and adjusts motor centers while movement is in progress

Dentate nucleus

Takes care of the output of the cerebellar hemisphere

Interposed nucleus (Globose and Emboliform)

Takes care of the output of the cerebellar paravermis

Fastigial nucleus

Takes care of the output of the cerebellar vermis and flocculonodular lobe

Spinocerebellum and Vestibulocerebellum

Are classified as reflex pathways in the cerebellum

Cerebrocerebellum

Its main function is motor planning and programming

Cerebral cortex through pontine nuclei

Is the input source for the cerebrocerebellum

Dentate nucleus

Is the output nucleus for the cerebrocerebellum

Dentate nucleus to motor, premotor, and prefrontal cortices

Is where the cerebrocerebellum output projects to

Anterior lobe syndrome

A cerebellar lesion causing gait ataxia

Posterior lobe syndrome

A cerebellar lesion causing intention tremor

Purkinje cells

Provide the sole output from the cerebellar cortex

Synaptotagmin

Protein that detects the entry of Ca2+ and is responsible for triggering vesicle fusion by binding with Ca2+

Calcium influx

Is proportional to the amount of neurotransmitter released at a synapse

Axon hillock

The area of a neuron with the highest integration of inputs

Spatial Summation

Occurs when excitatory inputs from a presynaptic neuron arrive at a postsynaptic neuron simultaneously, producing greater depolarization

Temporal Summation

Occurs when repeated excitatory inputs from a presynaptic neuron arrive at a postsynaptic neuron in rapid succession

Calcium accumulation in the presynaptic terminal

Possible reason for greater neurotransmitter release during facilitation, augmentation, and post-tetanic potentiation after tetanic stimulation

Nucleus Accumbens

A key structure in the limbic system considered the interface between desire and action, regulating emotions and motivation, and exhibiting increased activity in the presence of rewards

Amygdala

A brain structure crucial for the formation of emotional memories, especially why bad memories with emotional tone are easily remembered

Insula

The brain locus for disgust, involved in the bodily experience of emotion

Anterior Cingulate Cortex

The brain locus for pain and sadness, involved in motivational, emotional, and cognitive processes

Orbitofrontal Cortex

The brain locus for anger

Activating + Pleasure

The cognitive psychology axes that elicit euphoria

Activating + Displeasure

The cognitive psychology axes that elicit fear/anxiety

Deactivating + Pleasure

The cognitive psychology axes that elicit calmness

Deactivating + Displeasure

The cognitive psychology axes that elicit sadness

Dopamine

Neurotransmitter from the Ventral Tegmental Area attributed to euphoria and motivated motor behavior in response to reward

Serotonin

Neurotransmitter from the Raphe nuclei involved in the regulation of mood and affect and implicated in enjoyment/depression

Norepinephrine

Neurotransmitter from the Locus coeruleus involved in attention to novel and potentially challenging stimuli and REM sleep inhibition

Nucleus basalis of Meynert

Main location of Acetylcholine in the forebrain, associated with attention and memory in the CNS

Acetylcholine (ACh)

Is a REM sleep generator

Acetylcholinesterase

Enzyme that degrades Acetylcholine to acetyl CoA and choline

Reduced Acetylcholine in the synapse

Is associated with mild cognitive impairment, memory lapses, or subjective cognitive impairment

Long-Term Potentiation (LTP)

A process involved in memory that can be carried by acetylcholine and facilitates learning through repetition

Glutamate

The principal excitatory neurotransmitter in the brain that plays a key role in learning and memory

Neurotoxicity

The potential effect of too much glutamate in the brain

Astrocytes

Cells that carry out the response to increased glutamate firing in the synaptic cleft to increase oxygen and glucose supply via cerebral-arteriolar dilatation in neurovascular coupling

Glycine

Major inhibitory neurotransmitter found in the brainstem and spinal cord

GABA

Major inhibitory neurotransmitter involved in sleep circuitry

Ventrolateral Preoptic Nucleus (VLPO)

Nucleus that sends inhibitory GABA signals to the monoaminergic and cholinergic systems in the sleep circuitry

Supraschiasmatic nucleus (SCN)

Receives light signals from the retina via the retinohypothalamic tract during the central sleep rhythm

Somnogens (e.g., adenosine)

Agents that cause sleepiness or drowsiness and accumulate with sleep deprivation

Glymphatic system

The brain waste clearance system whose drainage function is increased during sleep

Anterograde amnesia

Inability to store new information, usually new biographical events

Retrograde amnesia

Inability to retrieve information acquired before the brain injury

Medial temporal lobe (MTL) damage

Related to the severity of both anterograde and retrograde amnesia

Hippocampus

A brain structure crucial for declarative memory formation and an important structure for learning as part of the Papez Circuit

Papez Circuit

Learned material reverberates in this circuit, which involves the hippocampal formation, fornix, mammillary bodies, mammillothalamic tract, and cingulate gyrus

Emotional tone

Contributes to memory becoming entrenched and is why bad memories are easily remembered, involving the amygdala and hippocampus

Habituation

Learning not to respond to repetitions of an insignificant stimulus

Sensitization

Increased responsiveness to innocuous stimuli that follow the presentation of a strong or noxious stimulus

Associative conditioning

Principles of memory established using the Aplysia model, including classical conditioning

Increased NT release and increased Receptor sensitivity

Occur in Long-Term Potentiation (LTP), a use-dependent increase in central synapse efficacy

"Neurons that fire together, wire together"

The principle describing Long-Term Potentiation

Depolarization and Glutamate binding

Required to open the NMDA receptor, which is both ligand and voltage-gated and partially blocked by magnesium

NMDA receptor

Allows calcium influx during Long-Term Potentiation after sufficient depolarization and glutamate binding

Working memory

A type of memory related to the prefrontal cortex and involves holding information for a short period, such as remembering a phone number

Semantic memory

A type of explicit long-term memory referring to general knowledge and facts, residing predominantly in the frontal and temporal cortex

Episodic memory

A type of explicit long-term memory referring to events of a person's life with subjective connotation and emotional response, related to the prefrontal cortex, limbic system, and cerebral cortex

Procedural memory

A type of implicit long-term memory referring to skills and habits, related to the basal ganglia/striatum

Basal Ganglia/Striatum

Brain structures related to implicit memory for skills and habits

Cerebellum

Brain structure related to implicit memory for simple classical conditioning of skeletal musculature

Amygdala

Brain structure related to implicit memory for simple classical conditioning of emotional responses

Left angular gyrus

Brain structure involved in calculation

Frontal lobes

Brain structures involved in insight, judgment, and planning (executive functions)

Attention

The most important step in memory formation, determining if sensory input moves to short-term memory

Maintenance rehearsal

Must be performed to keep information in short-term memory, such as rereading study material

Connecting new information to old information

Necessary during the encoding and consolidation process for long-term memory storage, requiring synapse formation

Retrieval and attention

Aspects of memory formation that are primarily affected in normal aging

Encoding, storage, and consolidation

Aspects of memory formation that are primarily affected in Alzheimer's disease

Cognitive Aging

Subtle decline over time in processing speed, sustained attention/multitasking, working memory, and word-finding

Normal Aging

Verbal ability, numerical/arithmetic ability, vocabulary, reading, verbal reasoning, and general intelligence remain stable or improve

Persistent or worsening forgetfulness

Is never part of normal aging

Mild Cognitive Impairment (MCI)

A stage between normal aging and dementia characterized by cognitive decline on testing/history but no functional impairment

Alcoholism, drug use, uncontrolled hypertension, diabetes, and high cholesterol

Factors that can expedite brain aging

Nucleus, mitochondria, endoplasmic reticulum, lysosome

Cellular structures that undergo changes in function and structure during aging

Lipofuscin accumulation, neurofibrillary tangles, amyloid plaque formation, decreased dendritic trees/axon numbers, demyelination

Microscopic changes that occur in the brain during aging

Volume loss, neurodegeneration in gray matter, demyelination in white matter, ventricular enlargement

Gross changes that occur in the brain during aging

Global Cortical Atrophy (GCA) scale

Used to classify the level of brain atrophy observed in aging

Wider sulci

A gross brain change seen in GCA 2

"Paper-thin" gyri

A gross brain change that may appear in GCA 3

GCA 1

Considered acceptable level of brain atrophy for individuals aged less than 75 years old

GCA 1 to GCA 2

Considered acceptable level of brain atrophy for individuals aged above 75 years old

Vibration sense

The sense most affected in the aging brain

Postural instability, axial bradykinesia, masked facies

Parkinsonian signs that are prevalent in a group of normal elderly individuals with a score greater than 2 on a related study

Tremor

Neurological sign that generally increases in incidence with age

Lateral gaze

Eye movement that is relatively limited compared to upward and downward gaze in aging

Changes from baseline abilities of an individual

What is considered in defining normal cognitive aging

Depression

Can be a risk factor for dementia later on and can overlap with memory issues, though memory issues in major depressive disorder don't necessarily mean dementia

Chronic lack of sleep

May increase the deposition of amyloid and tau proteins

Consciousness

A state of awareness of self and environment that gives significance to stimuli, composed of arousal (ARAS) and cognitive functions (Cerebral Hemisphere)

Responding to stimuli

Required for a patient to be considered conscious

Ascending Reticular Activating System (ARAS)

System that subserves arousal and is believed to consist of the monoaminergic and cholinergic systems put together

Pons -> Midbrain -> Thalamus -> Diffuse to both hemispheres

The pathway of the ARAS

Metabolic coma

A type of coma that is reversible if inducing factors are identified and addressed